1. Field of the Invention
The present invention relates to a machine forming, filling and sealing sacks and the like, starting from a continuous, flat, tubular strip, either straight or folded, of heat-sealable plastic material.
2. Description of the Prior Art
Presently known machines of the type indicated above are not without problems and disadvantages of both a practical and a functional nature. The main problem is due to the somewhat complex system used to move the empty sacks from the forming station to the filling station, and from the latter to the sealing station for the full sacks, as the devices provided to perform the above mentioned operations are in a fixed position, and the sacks must therefore perform a series of vertical and horizontal movements to avoid interfering with said devices, which causes an extension of the operating times and machine working cycle.
As will be shown more clearly during the course the present description, further disadvantages can also be seen in these conventional machines. For example in the systems for loosening the empty sack and tightening the full one, the sacks are gripped by respective translation gripping means, respectively to open the mouth of the former ready for filling and to cause the edges of the latter to adhere ready for sealing of the mouth thereof. Another disadvantage relates to the fixed suction cup systems for widening of the sack for filling.